With Microsoft getting ready to ship its new Vista operating system, experts who have been evaluating it for use within corporations are praising its security enhancements while fretting about the finer points of implementation.

Five years in development, Vista is supposed to ship to enterprise customers by the end of this month, two months ahead of its general release to consumers. Microsoft declared the Vista code complete this week, releasing it to manufacturing along with Office 2007.

"It's certainly the most secure operating system they've released to date," said Erik Schmidt, a technical manager at the University of Florida, which has been evaluating Vista on more than 50 personal computers as one of the formal beta testers in Microsoft's Technology Adoption Program.

That perspective was echoed by another TAP participant, Keith Dickey, a project manager in Fulton County, Georgia. Dickey said that a new feature within Vista called user account control—which administrators can turn on to prevent the installation of unauthorized applications—will allow the county to cut back on the 24,000 hours it spends each year cleaning up infected machines. That will translate into about $750,000 that the county's chief information officer, Robert Taylor, can devote to something else.

Some of the new Microsoft security enhancements may be complicated to use.

One is BitLocker, a feature that encrypts the entire contents of a hard drive so that a stolen laptop can't become a source of pilfered intellectual property. BitLocker's policy of looking for changes in a PC's BIOS may occasionally activate the shutdown mechanism when it isn't needed. BitLocker "is a very very good idea," said the University of Florida's Schmidt. "But it can be dangerous if you don't know what you're doing."

Besides the security features, perhaps the most notable change in Vista compared with Windows XP is a slick user interface that is reminiscent of the UI in Apple's OS X.

The good news about Vista's UI, Aero, is that it makes it much easier to switch between applications. The bad news is that Aero requires "a significantly more powerful graphics card than you would typically find in almost all corporations," said Ben Downe, a London-based senior associate at Diamond Management and Technology Consultants. Downe has been evaluating Vista for his Global 1000 clients over the past few weeks.

In any event, it's the rare enterprise that will rush out to install Vista when it becomes available later this month. Big-company CIOs are naturally wary about the stability of any new OS, and want to test compatibility with third-party applications.

"XP is a good operating system," Gartner analyst Michael Silver said. "There's really no rush to get off of it."